Apparatus for treating metal sheets



April 19, 1932. E. GRIFFlTl-is E11-'AL 1,855,107

APPARATUS FOR TREATING METAL SHEETS Filed July '9, 1929 5 Sheets-Sheet l w24/ I @Zweig/@4 @WM @if l April 19, 1932. E. GRlFr-lTHs ET AL APPARATUS FOR TREATING METAL SHEETS Filed July 9, 1929 5 Sheets-Sheet 2 s w W @w Nw Z i I E. GRIFFITHS ET AL APPARATUS FOR TREATING METAL SHEETS April 19, 1932.

Filed July 9,' 1929 5 Sheets-Sheety 5 Z @Z4/W@ www4 f @Sk MEQ QSA* @S www@ mw. .mw

April 19, 1.932- E. GR|FF|THs E' AL 1,855,107

APPARATUS FOR TREATING METAL SHEETS Filed July 9, 1929 5 Sheets-Sheet 4 April 19, 1932. E. IGRn-'FITHS ET AL APPARATUS FOR TREATING MET`AL SHEETS Filed July 9, 1929 5 Sheets-Sheet 5 We :id

Patented Apr. 19, 1932 UNITED STATES,

PMEN T; OFFICE `ERNEST GRIFFITHS,OF LIVERPOOL-ENGLAND, AND EVELYN mJWN GBIFFITHVOF MUMBLES, SWANSEA, SOUTH WALES APPARATUS .FORTREATING METAL-SHEETS Application lediuly 9,1929,ser1a1Nof376,94o, and iniereat lBritain July 31, 1.928.

This invention relates to 1 an improved:

method of and apparatus' for 'continuously annealing and cooling metal-sheets;

According tothe invention `the sheetsare.`

`the sheets through the furnace and cooling chamber `is eected is so arranged-'that the sheets are supported by their topedges, and so that the main portion of the part ofthe conveyor carrying the sheetsvvithin` the furnace is protected from the vdirect action of r they gases, the return portion being exposed to the air for cooling or'enclosed in an insulated duct to conserve its heat with inspect-ion" covers in same in such manner-that it isaecessible for repair Without dismantling, and

,- may easily be inspected While-running,theroofs of the furnace, cooling chamber' and conveyorbeing detachable so that they may readily be removed for repair. The coolinglnedium in the cooling chamber isfpreferably the producer gas `or other rfuel gas for the furnace, the cooling chamber Vbeing soA constructed that air is excluded therefrom so as to prevent combustion of the fuel gas in .the said chamber, said gas in this Way being preheated; the arrangement also permitting the products of combustion, on leaving 'the annealing furnace, toV be passed throu 'a recuperator in Which they are adapte' to heat the combustion air for the furnace, and thus reduce the fuel consumption. Each sheetis` supported from a conveyor 'by its top edge, any suitable form of gripping devices on the conveyor may therefore be employed vto hold the said top edge; but if the sheets requirente'` z emerge from the process withoutlany marking, such as would result from the gripping:-

of the-.upper edge, or Where such gripping, due to contact with partsA cooler than the4 sheet', would prevent ltheto'pfedge from being raised' to the desired temperature, the sizeof the sheets fed to thefurnace .is .so arrangedA that at any stage in the process after ytheisheetV has been through the furnace, a thin strip yis cut off that edge of the sheet which Wasuppermost asfit passed through the furnace, 'thus bringing the sheet to the standard sizev rei: quired.

We find With exceptionally thin sheetsof a comparativelyy large size that, in addition `to bending the top edge over at an acute .angle'as described, a reverse fbend should be` given so `that the 'configuration of the transverse section ofthe edge portion hasa vdouble fold. i The sheets may be passed throughthe furnace in linein the one vertical plane.

The suspension of the sheets edges enables the sheets `to be singly annealed Whilst avoiding the difficulties SeX- periencedf according to present practice in Which'the'sheets are carried on conveyors with theirV planes horizontal, or Awith the sheets bentto convex shape; in suchI cases the sheets, When-raised to annealing 4tem'-r perature, become soft, and unless they are supported atvnumerous points, the sagging due to their Weight distorts them. i i

When suspended-by their upper edges, .according to the present invention, Whether moving in line or broad-side on,"the `Weight of the sheet tends to Amaintain each part'of.' the 'sheet in the sameverticalV plane.` The sheets may befed and removed from the con` veyor byautom'atic means or by hand.Y

The fuel gases are first fed to the cooling chamber, and as airi's'excluded from thelatter, combustion cannot take place; the sheets are,however, effectively cooled and the said gas, which is preferably washed-producen gas, is .thus raised in temperature before it enters the furnaceor combustion chamber. The products of combustion ofthe-annealing. furnace are led by a flue to a recuperator or heat exchanger `in which, for example,- the combustion air for the'annealing furnace mayv i be pre-heated.- Wherethe yproducts off comL by their top L Y chamber are arranged in accessible positions 1 Fig. 1 is a transverse section ofy a vtions of said construction. Figs. 8, 9-and 10 are elevations.

where they are not subject to the actionl of the furnace gases, and in which they may be repaired without general dismantling.k

rThe conveyor chains, armsv and furnace track are preferably made of a material which has a high tensile strength at high temperature so that the furnace conveyor be stopped and started if desired with the furnacelitup.. f

We have illustrated ourinvention in the accompanying drawings, in vwhich cooler and conveyor` suitable for sheets fed in line, the plane of section being taken on the line 1, 1 of Fig. 2. Y Y

Fig. 2 is a section to a smaller scale. Fig. 2A is a detail ofthe sealing rollers.

Figs. 3 toB show details of construction ofthe conveyor,- carrierbarsand clips suitable for use when the. sheets are fed in line to the furnace. Y

-. Fig. 3 being an elevation in transverse section; Yand i f Fig. 3A a side view of a part ofv Fig. 3.

Fig. 4 is an elevation, in transverse section., of a modification, and Fig. 4A is a perspective view ofthe carrier shown in Fig. 4.

Fig. 5 a front elevation of a further the clip.v f y Fig. 5A a part section on a transverse plane passing medially through F ig. 5 g. and

Fig. 5B is a fragmentary detail view of a cross section of the carrier bar D and shoe d3. Fig. Gis a view similar to Fig. 1 showing the arrangement when the sheets are fed with their planes at right angles tothe direction ofmotion.

Fig. 7 is a corresponding' longitudinal section to a smaller scale.- Y

Figs. 8, 8A and 8B show details of construction of a conveyor and carrier bars suitable for sheets supported with their planes atright angles to the direction of motion.

Figs. 9, 9A and 9B show details of a modification of the last mentioned construction, and Figs. 10 and 10B show further modifica- In these views form of yFigs 8A and 9B are plan views;,and Fiofs. 8B, 9B and. 10B are end elevations C a in transverse section.

Figs. 11and. 12 are part transverse sections of the furnace showing the mode byf which the'conveyor chamber is sealed from l tofacilitat'e the withdrawal of anyV of the the furnace. I

Figs. 13 to 18 show the different modes in which the upper edge of ther sheet may be treated for attachment purposes.

furnace,-

Figs. 13, 15 and 17 being side elevations;

Figs. 14, 16 and 18 front elevations, and

Fig. 19 a view showing the mode in which a perforated sheet may be utilized without cutting off the edge.

Fig. 20 is an elevationv of an adjustable opening.

` Referring first to Figs. 1 to 5 which illustrate an arrangement when the sheets are fed through the furnace with their planes in a common vertical plane:

A is the furnace which may be of any suit rier bars D of the conveyor protrudeand tov the inner ends cl2 of which bars the sheets are Aattached yas hereinafter. described. y

lThebars D are attachedto links of a conveyor chain l1 which traverses the chamber B from end. to end; passingv over. sprocket wheels K, K', the wheel K being at the front of the furnace and the wheel K being at the rear end ofthe furnace or where the furnace is combined with a cooling chamber H as in Fig. 2, the conveyortraverses both the furnace and the cooling chamber, the wheel K being in rear of the cooling chamberg. the planeof rotation of the wheels K, K -is pref* erably as shown in 'chain dotted lines k1, k1 Fig. 1, the axis of rotation being k2, k2. The return portion of the chain Z1 .which extends outside the furnace is shown in Fig.

1, 'and the oblique arrangement of the.

sprocket-wheels has the advantage of saving space and of relieving the guides on the rey turn journey of the ,weight ofthe conveyor bars.l i v ln the preferred arrangement there are three fixed guide rai-ls, e1, c2, e3 supported at intervals on a frame E, and the bars D (see Figplare provided with'three shoes J3. (Z4, and d5, the form-ertwo resting on the guides e2, e3 and the latter pressing upwardly.V

on the guide e1, the guides thus'serving to hold the bars D horizontal as they pass rection shown in Fig. 1 as theyreturn outside the furnace. rFhe'shoes (Z3 and Z4 rest onthev sheets as 'theyl are bev-ing con.

- through the furnace and'in the inclined di Y veyedthrough' the furnace and cooling chamber.

In order to prevent escape of heated gases from the furnace and in order to prevent the access of'air to the cooling chamber H, pairs of seal-ing rollers F are fitted at the entrance to the furnace; similar rollers F2 and F3 are fitted respectively between the furnace and the cooling chamber H and at the outlet to the cooling chamber. These rollers are car ried in bearings f2, f3 and their peripheries abut with a yielding pressure and they are encasedin housings f1 which housings and rollers seal the entrances and exits with the exception, of course, of openings at the top justwide enough to permit the passage of the ends of the carrier bars D. h1 is the top of the cooling chamber, h2 the inlet for the cooling gas (which preferably is the gas employed to heat the furnace, and which may be a washed producer gas) the cooling gas is preheated by heat transmitted to it from the cooled sheets. This gas leaves the cooling chamber by the outlet h3 and passes to theV furnace burners.

As Stated, the sheets may be attached by their upper edges to the ends of the carrier bars D3 in any convenient manner. We have, however, by way of example, shown three methods of attachment of the sheets in Figs. 3, 4 and 5 respectively, these three methods relating 'respectively to ;-sheets which have their ends turned over as shown in Fig. 13 or Fig.l 15; sheets having a plain upper edge adapted to be gripped; and sheets. punched with holes c3.

Referring first to Figs. 3 and Ag-the bars D have a turned down portion (Z6 ending in an angled portionclQ on which rests the turned over portion c1 of the sheet C, see Figs. 13 and 14; each sheet is supported by several, say four, bars. Gr are grippers or clips pivoted on the studs g1 attached to the hars D, and having anangular lower portion g2 which presses the portion c1 of the sheet into contact with the angled portionclQ; where the sheets have a second bend such as c2, Fig. 15, the portion c2 extends behind the portion g2 so that however thin the sheet C may be, and however hot its edges `may be,

itis not possible to draw the bent parts through the gripper. Each gripper is provided with a pin g3 which, at that point in the travel ofthe conveyor at which the sheets have to be attached to the conveyor, or be detached therefrom, engages with a cam bar g4 which turns the gripper about its stud g1 into the position shown in dotted lines Fig. 3A, the cam bar permitting the gripper, when the sheet is in position, to turn about its pivot and grip the sheet as described.

Where the thickness or size of the sheets is such fthat they may be attached to the carrier bars D- by simple gripping pressure, the arrangement/is modified as shown in Fig. 4.

The end of the carrier bar D1 .has aturned down portion Z7 which 'carries a suitable fac-- ing with which the outer face of the upper edgefof the sheet engages, `the sheet being gripped between this facing and a corre'- sponding facing on the depending portion gt3 of a gripper lever G pivoted at g5 and provided at the other end with a weight g? which gives the gripping pressure. Said weight has a surface g8 which` is-adapted to make contact, at the appropriate times, with a cam bar g9 whichraisesit and so releases thegripping pressure .of 96,' and permits the sheets to be inserted and removed. 1n orderto protect the corners of the sheets against accidental bending, the ends of certain of the grip per bars may each be provided with a channelf shaped piece Z8 between the depending sides of which the top corner of the sheet- C is housed.

Where it is permissible to provide 'the upwith a turned down end Z9 carrying apinor hook 03, the sheets being held inposition by a formed on the carrier har D2. The grippers are provided with slots JQ12 which fit over the pins 310and each gripper has a lever Q11 adapted, when the sheets have to be attached to the carrier bars, or have to be detached' therefrom, fo engage a cam har` g1?) which lifts the gripper 2 clear of the pins d10.

Referring now to Figs. 6 to 10 ,-in this case the sheets C are adapted to be conveyed through the furnace A and cooling chamber H with their planes at right angles to the direction of motion, an arrangement which permits, with a given size of furnace, an increased number of sheets to be in the furnace at a given time and consequently a longer heating and cooling period to be given to the sheets. In this arrangement there is a'conveyor chamber B on each side of the furnace top, each chamber communicating through a longitudinal slot b1 with the furnace. There are two chains d1, one passing through each chamber B", and there is a guide rail e4 in each chamber B.

planes of rotation are vertical, the conveyor passing back along the guides e5 carried by girders e6 supported by 'columns e7; the arrangement being such as to leave Aclear for lifting the furnace cover, which in this case is made in two halves a2, a3, having a Vcentral J10 which pins when the sheets are placed in position are hooked into the holes' The pairs of sprocketl wheels K2 and K3 are arranged so that their gripper G2 pivoted at g1() in brackets g24 95 `terfering with the conveyor; in order to give a straight lift clear of the conveyor, eye bolts a by which. the covers are raised are located near the outer sides of the covers, and balance weights a4 are fitted to the covers so that the Centre of gravity of each half is approXi mately below its eye bolt a5. The conveyor bars D3 extend across from the one chamber B to the other and are thus supported by the guides e4, and driven by chains Z1 at each end..

Figs 8, 9 and 10 show arrangements for attaching the sheets to the carrier bars, the arrangements being respectively applicable to sheets, the upper edges of whichvare bent, to

sheets having plain upper edges, and to sheets perforated on their upper edges.

Referring first to Figs. 8, 8A and 8B;-

D3 is the gripper bar supported at each end `by shoes Z13 and connected at each end to a Y conveyor Chain d1. Thebar has depending 60T conveyor Atravel atwhich the sheets have to portions Z12 similar to those of Fig. 3, and each depending portion is provided with a gripper G3 pivoted at glt to the bar D3 and Ahaving a lever portion g the ends of the levers g15 being adapted to engage with respective cam bars glfand the bars 916 are so shaped that all the vgrippers are moved intothe position shown indotted lines on the "left hand side of Fig. 8 when sheets have to be inserted or be removed. The sheets may bebent as shown invFig. 13 or Fig. 15 as may beY most convenient.

In the arrangement shown in Fig. 9 and T QAeach gripper bar D4: has depending engagthe travel of the conveyor at which the sheets have to be inserted or removed. In this ar rangement the top edges of the sheets are plain.

Fig. 10 shows the arrangement when the top edges of the sheets are perforated with holes 03. In this case the carrier bar D5 is provided with a series of pinsor hooks 16 to take the holes c3 in the sheets, and the latter are held inpostion by the gripper G5 pivoted at xQ21 in brackets i517 carried from the bar D5. VThe gripper bars are slotted as shown at 926 to clear the pins (16, andthe gripper has a lever extension g22 adapted to engage with the cam bar 923 at points in the be inserted or removed.

In the broadside arrangements of the sheets itis of course notY possible to employ the sealing rollers F described in connection i with Figs. 1 and 2; the openings at the inlet to be treated, the opening P being, adjusted as shown in Fig. interchangeablesliding plates or baiiies p1, of various-widths, are

slidably attached to the fixed end plates.; and` horizontally adjustable side baffles 'p3 areY fitted which are adjusted to suit the `Width of the sheet. Y

Where the sheets are suspended aslshown in Fig. 2 overhung carrier Vbars are preferred, and where the sheets are suspended as shown in Fig. 7 carrier bars supported at both ends are preferred, but either arrangement of carrier bar may be used for either mode of supported sheet, or the conveyor may run above the roof and the carrier bars hung down through a slot in the roof.

Where it is desired to prevent 4access of hot gases to the conveyor chambers B through the longitudinal slot o1, sealing arrangements as shown in Figs. 11 and 12 may be adopted. In Fig. 11 each carrier bar is provided with a V shaped part g1,this part g1 dips into a sealing liquid Q inthe continuous V shaped trough g2 into `which liquid dips a fixed longitudinal sealing member Q3;

In Fig. 12 the part g1 depends into aY trough g4 a longitudinal depending piece. 93j

being Afitted as Iiefore. In this case an air seal is relied upon. y

Where the top edges of the sheets are bent l.

over as in Fig. 13 or Fig. 15, or punchedas in Fig. 18 these edges may, as stated, be sheared off by the tinplate maker, or the'bent portions may be straightened`V and the straightened and punched sheets delivered to the user, who, in the act of stamping the parts of ymetal boxes or the liketo be manufactured discards the portions j which are unsuitable ;-'for instance the punching of the boX lid c4@ r or the like may be accomplished as shown in Fig. 20 so as to vreject the portions of the sheets punched with the holes" c3. v

I-Iaving now fully described our invention, we declare that what we claimrand desireto secure by Letters Patent, is

1. In apparatus for annealing metalsheets',

in combination ;-afurnace; a conveyor traversing the furnace and having carrier bars the ends of which extend downwardly into the furnace; sheet supporting means,

carried by the ends of the carrier bars andv extending from .the said'ends beyond the upper edges of vertical sheets to'be conveyed and adapted to hold the sheets against down-v ward vertical movement;` grippers carried by the said bars adapted to engage the upper portions of the sheets .and to'retainthem in position on the said supporting means.

2. In apparatusV for annealing y metal sheets, in combination;'a furnace;l a conveyor traversing the furnace longitudinally and having carrier bars the ends of which y extend downwardly into the furnace; sheet supporting means carried by the ends of the said carrier bars and adapted to engage with the under sides of the turned-over upper edges of the sheets to be conveyed, and griptraversing the said compartment and having.

carrier bars extending through said opening into the furnace, supporting means extending upwardly from the ends of the carrier bars within the furnace, and adapted to be engaged by the undersides of turned over top edges of the sheets, and grippers carried by the said bars adapted to engage the upper parts of the said turned over edges to hold the edges of the sheets in position on said supporting means.

4. In apparatus as claimed in claim 3, in which the grippers are pivoted to the carrier bars, members carried by the grippers, and fixed cams having parts inclined to the path of the pivots of the grippers which cams when the grippers reach the point at which the sheets have to be attached to or removed from the conveyor move the said members to open the grippers, substantially as described.

5. In apparatus as claimed in claim 3, in which the conveyor is an endless chain the conveying part of which passes through the conveyor compartment and the return part of which passes outside the furnace, sprocket wheels located at opposite ends of the furnace the planes of rotation of which are inclined to the vertical so that the said return portion of the conveyor outside the-furnace is at a lower level than the part of the conveyor within the furnace, substantially as described. i

6.V In apparatus for annealing metal sheets, in combination, an elongated annealing furnace, a compartment disposed parallel with the upper portion of the furnace and communicating with the furnace through a narrow longitudinal opening, a conveyor passing through said compartment, carrier bars on the conveyor passing through the said opening into the furnace, supporting means on the said carrier bars to carry the sheets, channel-shaped portions formed on the parts of the carrier bars in said opening, a longitudinal member depending from the top of said opening into the said channel-shaped portions, and a fixed channel member extending longitudinally along the bottom of said opening under and receiving said channel portions ofthe carrier bars and, adapted with `said portions andssaid longitudinal member kto make a fluid-tight seal between-the conveyor chamber and the furnace, substantially. as described,

7. Apparatus normally occupying sheet grippingrelation,

one member of each pair being movable kaway from the other to effect the releasing of-,fthe

sheets, and onel member; of each pair being provided withan'upwardly directed pin and the other member being provided with an opening for the reception of the pin.

8. Apparatus for annealing metal sheets, in combination, an elongated furnace, a longitudinally disposed compartment separate from the furnace but communicating with the upper part of the furnace through a narrow longitudinal opening, a conveyor traversing said compartment and having carrier bars for the sheets extending into the furnace through said opening, and means for preventing furnace gases flowing through said opening into said compartment while permitting movement of the carrier bars along said opening.

9. Apparatus for annealing metal sheets, in combination, an elongated furnace, guide rails extending longitudinally of the furnace in relatively spaced relation, shoes slidably mounted on the guide'rails and provided with downwardly directed flanges contacting with the inner sides of the rails, carrier bars for the sheets secured to the shoes and having certain ends thereof provided with sheet suspending means, a guide rail located above the other ends of the carrier bars to prevent their displacement from said first guide rails, and means by which shoes and carrier bars may be moved along the guide rails.

10. Apparatus for annealing metal sheets, including a furnace, a conveyor traversing the furnace and having horizontally disposed carrier bars provided with downwardly directed terminal portions, members extending upwardly and outwardly from said terminal portions and adapted to be engaged by the undersides of turned over top edges of the sheets, grippers engaging the upper sides of said turned over edges above the upperVV for.V annealing metal sheets, in combinatioma conveyor traversing the furnace and having carrier bars, and meansV lfor suspending the sheets from the carrier A bars and including pairs ofcooperating sheet rgripping members, theinembers of each V.pair

ll. Apparatus for annealing metal sheets,

carrier bars provided with downwardly di-V rected terminal portions having a fixed position with relation thereto, members depending,` from the carrier bars and pivoted thereto for movement toward and away from said terminal portions, said terminal portions and members constituting sheet gripping means,

Y f levers located above the carrier bars and ixed to said members, and providing means by which said members maybe moved toward or away from said terminal portions, and lo weights carried by said levers and normally acting to move them in ay direction to urge said members toward said terminal portions.

In testimony whereof, wie affix our signav tures. Y ERNEST GRIFFITHS.

EVELYN EDWIN GRIFFITHS. 

